Common Code Issues Found During Home Inspections.
Home inspections often reveal plumbing issues that can delay closings or require urgent repairs. Understanding these common code problems can help agents, buyers, and sellers prepare, avoid surprises, and keep transactions on track.
Pro Tip for Agents and Buyers
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Address these issues proactively before listing a property or as soon as they’re flagged during inspection. Quick repairs can prevent delays, renegotiations, or lost deals.
1
Water Heater Drain Lines, Temperature & Pressure Relief Valve, & Expansion Tank
What it is:
Water heaters must have a temperature & pressure relief (T&P) valve with a drain line to safely discharge excess pressure or hot water. Many modern homes also require a thermal expansion tank, which absorbs extra water volume as it heats and expands—especially in closed plumbing systems.
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Why it matters:
A missing or improper T&P drain line is a safety hazard, risking water damage, scalding, or even a tank explosion. Without an expansion tank, excess pressure can damage pipes, fixtures, or the water heater, causing leaks or triggering the T&P valve to drip.
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What to check:
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T&P drain line: Approved material (no flexible hoses/PVC on gas models), no upward slopes, terminates within 6 inches of the ground outside—never left open in attics or crawlspaces.
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Expansion tank: Present if required, properly installed, not leaking, and air pressure matches home water pressure (40–80 psi).
2
Gas Venting Issues
What it is:
Gas water heaters and some appliances require proper venting to safely exhaust combustion gases (like carbon monoxide) outside the home.
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Why it matters:
Improper venting can allow dangerous gases to enter living spaces, risking health and safety.
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What to check:
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Vent pipes should be securely connected, sloped upward, and free of rust or holes.
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Double-wall venting is required in many cases.
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Vents must terminate outside, not in an attic or crawlspace.
3
Old, Leaky Fixtures
What it is:
Older homes often have faucets, valves, and toilets that drip, leak, or don’t shut off properly.
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Why it matters:
Leaks waste water, increase bills, and can cause hidden water damage or mold.
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What to check:
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Look for visible drips, corrosion, or mineral buildup on faucets and valves.
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Toilets that run or don’t flush completely.
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Evidence of water stains under sinks or around fixtures.
4
Leaks Under the Home (Crawlspace or Slab)
What it is:
Hidden leaks in supply or drain lines under the home can go unnoticed until an inspection.
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Why it matters:
These leaks can cause structural damage, rot, and mold, and can be costly to repair.
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What to check:
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Inspect crawlspaces for dampness, puddles, or moldy smells.
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On slab homes, check for unexplained increases in water bills or warm spots on floors (hot water leaks).
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Ask if a camera inspection or leak detection has been performed.
5
High Water Pressure (Missing or Failing Pressure Reducing Valve – PRV)
What it is:
A PRV is a device that reduces incoming water pressure to a safe level for the home’s plumbing system.
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Why it matters:
High pressure can damage pipes, water heaters, and fixtures, causing leaks and premature failure.
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What to check:
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Water pressure should be between 40–80 psi; anything higher is a code issue.
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PRVs are typically located near the main water shutoff; check for presence and signs of leaks or corrosion.
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If pressure is high or fluctuates, a plumber should inspect and replace the PRV if needed.